In order to get the plant that you are looking for at any Garden Center, you ask for it, right? What if you asked for a specific plant and they game back with something not even close to what you were asking for? This is the problem with common names of plants.
Here's an example:
You walk into a nursery in the South and ask for a "Confederate Rose", you are probably looking for a Hibiscus, right? Looks something like this.
What if they came back with something that looked like this?
Either one would be theoretically correct. You used the common name, 'Confederate Rose" The first one, the one you were probably looking for is Hibiscus mutabilis. The other one is Agave parrasana. Two completely different names for two completely different plants. This is the problem with common names. They are usually easy to remember but two different people might be talking about two different plants, especially if they were raised in different parts of the Country or World!
When I was working on becoming a Certified Professional Nurseryman, I had to learn hundreds of botanical names. It has served me well, I don't usually have the problem like I mentioned above.
I know what you are saying all those Latin terms, it is way too hard. Believe it or not, you probably use the botanical name for many of the plants you now grow. How many of you grow, Magnolia? That is the botanical name. Don't believe me, Look up any of these:
That's just a small list of the Magnolias.
How about Camellia? Nandina, Begonia, Bougainvillea, Phlox? Even when we are discussing my beloved Citrus. Citrus is the botanical name:
Citrus sinensis (Sweet Orange)
Citrus paradisi (Grapefruit)
The list goes on and on. Now, I admit, MOST of the plant names we do not use on an everyday basis.
Learning them can be fun though. Sometimes they will give you an idea of where they come from. Camellia japonica for example. Kind of sounds like Japan, right? That is where the originated from. How about Pinus canariensis? This is the Canary Island Pine.
Botanical names do not have to be hard, if you don't want them to be.
Some will even be funny and tell you something about who discovered them. Discocactus horstii.... It was named after the Brazilian collector Leopoldo Horst. I don't know if he enjoyed Disco music or not, but it is a "Far Out Cactus"
I am not going to try and get Scientific on you, if you want to learn more about WHY plants have two names, check out this website:
He has done a very good job explaining it.
For now, I encourage to look up some of your favorite plants and learn their botanical name. Then, maybe next time you are chatting with somebody and they want to know "How is your Fig doing?" You can say, "Oh, my Ficus carica is doing well, Thank You!" Unless they meant your houseplant the Rubber Tree, then it is your Ficus elastica! See the fun you can have!?